diff options
| -rw-r--r-- | mm/mincore.c | 76 |
1 files changed, 27 insertions, 49 deletions
diff --git a/mm/mincore.c b/mm/mincore.c index f77433c2027..1f6574c5167 100644 --- a/mm/mincore.c +++ b/mm/mincore.c @@ -54,7 +54,7 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff) * all the arguments, we hold the mmap semaphore: we should * just return the amount of info we're asked for. */ -static long do_mincore(unsigned long addr, unsigned char *vec, unsigned long pages) +static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *vec) { pgd_t *pgd; pud_t *pud; @@ -64,35 +64,29 @@ static long do_mincore(unsigned long addr, unsigned char *vec, unsigned long pag unsigned long nr; int i; pgoff_t pgoff; - struct vm_area_struct *vma = find_vma(current->mm, addr); + struct vm_area_struct *vma; - /* - * find_vma() didn't find anything above us, or we're - * in an unmapped hole in the address space: ENOMEM. - */ + vma = find_vma(current->mm, addr); if (!vma || addr < vma->vm_start) return -ENOMEM; + nr = min(pages, (vma->vm_end - addr) >> PAGE_SHIFT); + #ifdef CONFIG_HUGETLB_PAGE if (is_vm_hugetlb_page(vma)) { struct hstate *h; - unsigned long nr_huge; - unsigned char present; i = 0; - nr = min(pages, (vma->vm_end - addr) >> PAGE_SHIFT); h = hstate_vma(vma); - nr_huge = ((addr + pages * PAGE_SIZE - 1) >> huge_page_shift(h)) - - (addr >> huge_page_shift(h)) + 1; - nr_huge = min(nr_huge, - (vma->vm_end - addr) >> huge_page_shift(h)); while (1) { - /* hugepage always in RAM for now, - * but generally it needs to be check */ + unsigned char present; + /* + * Huge pages are always in RAM for now, but + * theoretically it needs to be checked. + */ ptep = huge_pte_offset(current->mm, addr & huge_page_mask(h)); - present = !!(ptep && - !huge_pte_none(huge_ptep_get(ptep))); + present = ptep && !huge_pte_none(huge_ptep_get(ptep)); while (1) { vec[i++] = present; addr += PAGE_SIZE; @@ -100,8 +94,7 @@ static long do_mincore(unsigned long addr, unsigned char *vec, unsigned long pag if (i == nr) return nr; /* check hugepage border */ - if (!((addr & ~huge_page_mask(h)) - >> PAGE_SHIFT)) + if (!(addr & ~huge_page_mask(h))) break; } } @@ -113,17 +106,7 @@ static long do_mincore(unsigned long addr, unsigned char *vec, unsigned long pag * Calculate how many pages there are left in the last level of the * PTE array for our address. */ - nr = PTRS_PER_PTE - ((addr >> PAGE_SHIFT) & (PTRS_PER_PTE-1)); - - /* - * Don't overrun this vma - */ - nr = min(nr, (vma->vm_end - addr) >> PAGE_SHIFT); - - /* - * Don't return more than the caller asked for - */ - nr = min(nr, pages); + nr = min(nr, PTRS_PER_PTE - ((addr >> PAGE_SHIFT) & (PTRS_PER_PTE-1))); pgd = pgd_offset(vma->vm_mm, addr); if (pgd_none_or_clear_bad(pgd)) @@ -137,43 +120,38 @@ static long do_mincore(unsigned long addr, unsigned char *vec, unsigned long pag ptep = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); for (i = 0; i < nr; i++, ptep++, addr += PAGE_SIZE) { - unsigned char present; pte_t pte = *ptep; - if (pte_present(pte)) { - present = 1; - - } else if (pte_none(pte)) { + if (pte_none(pte)) { if (vma->vm_file) { pgoff = linear_page_index(vma, addr); - present = mincore_page(vma->vm_file->f_mapping, - pgoff); + vec[i] = mincore_page(vma->vm_file->f_mapping, + pgoff); } else - present = 0; - - } else if (pte_file(pte)) { + vec[i] = 0; + } else if (pte_present(pte)) + vec[i] = 1; + else if (pte_file(pte)) { pgoff = pte_to_pgoff(pte); - present = mincore_page(vma->vm_file->f_mapping, pgoff); - + vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff); } else { /* pte is a swap entry */ swp_entry_t entry = pte_to_swp_entry(pte); + if (is_migration_entry(entry)) { /* migration entries are always uptodate */ - present = 1; + vec[i] = 1; } else { #ifdef CONFIG_SWAP pgoff = entry.val; - present = mincore_page(&swapper_space, pgoff); + vec[i] = mincore_page(&swapper_space, pgoff); #else WARN_ON(1); - present = 1; + vec[i] = 1; #endif } } - - vec[i] = present; } - pte_unmap_unlock(ptep-1, ptl); + pte_unmap_unlock(ptep - 1, ptl); return nr; @@ -247,7 +225,7 @@ SYSCALL_DEFINE3(mincore, unsigned long, start, size_t, len, * the temporary buffer size. */ down_read(¤t->mm->mmap_sem); - retval = do_mincore(start, tmp, min(pages, PAGE_SIZE)); + retval = do_mincore(start, min(pages, PAGE_SIZE), tmp); up_read(¤t->mm->mmap_sem); if (retval <= 0) |